StoreKit has a bug that can lead to incomplete downloads being marked as "Finished".
I have seen some apps that download large files after In-App Purchases do an integrity check on them. How is this done?
Something I do in my own app is to pass a JSON with a list of resources will be downloading. Beside passing the URL of the resource, I also pass the checksum of it. After the download for a given file I compared the checksum I have from the JSON with the checksum of the file itself. You can use something like this.
Related
I have created some asset bundles from my Unity assets using the directions given in the Unity documentation section on AssetBundle Workflow. After running the "Build AssetBundles" command, each asset bundle results in four files: myasset, myasset.meta, myasset.manifest, myasset.manifest.meta.
Now I am ready to deploy these bundles to a web server and implement downloading/caching in my Unity project. I have found numerous examples such as this that show the download URL to be a single file with a .unity3d extension. This is leading me to conclude that I am missing a step - I assume that all four of my files will be required by the app and that I have to do something to combine them into a .unity3d file first.
What file(s) do I need to deploy? Are there any additional steps that I need to take before my file(s) are ready to upload? Thanks in advance for any advice!
Just myasset will suffice.
Sometimes people optionally add .unity3d as a filename extension to their Asset Bundles. It is just a community convention, and is completely optional. Source (copied below)
Vincent-Zhang
Unity Technologies
Just a reminder, we don't have an official file extension ".unity3d" for asset bundle, it's not mandatory. You can use whatever file extension as you want, or without file extension.
But usually people use ".unity3d" as the file extension just because we used it in the official sample code at first time...
Unity creates the .meta files for all assets- you don't have to worry about those. In short, your myasset file is enough. I do not add file extensions to mine. Do note that if you use the strategy shown in the example that you shared that the client will re-download the bundle from the server every time. You need to additionally provide a version number if you want to take advantage of caching. You can see this in some of the method overloads here, the ones that have a Hash128 or uint "version" parameter. Caching is great because you can use the bundle that is already saved on the device next time instead of downloading from the server when no changes have occurred. The version/hash number you provide essentially gets mapped to the file name. Whenever a matching version is found, the file on disk is used. Update the version number to something else when the content changes to force the client to download anew.
You may want to reference the .manifest file for the CRC value listed there. You may have noticed a crc parameter in the link I shared as well. This can be used to ensure data integrity during transmission of the bundle data. You can make sure the downloaded content's CRC matches that of the bundle when you created it.
I want to know if there is a 'right' way to make file uploads through custom tools.
I've seen the https://confluence.sakaiproject.org/display/BOOT/File+Uploads+with+RSF guide and it seens ok, but It stops with the file in memory with no further info. I can built a random file upload code but I want to make it Sakai-friendly (Using ContentHosting and Resources service?)
Any hints?
Thanks
The link you provided for the first part is a good example of how to get the upload initially processed. Going through RequestFilter will get your files validated, but you can use whatever method you want to upload it.
For the second part, I'd look at the ContentHosting webservice (createContentItem) for an example of how to add a file from a byte[] in memory after you've uploaded it.
These methods in ContentHostingService also accept InputStream as a parameter as of 2.7 (KNL-325), so you don't have to store the entire file in memory and can stream it as you're uploading, which you should do if the files are of any reasonable size.
I've experimented with several ways on seeing if I need to update my user's UITableView data source only if the server one is newer. Over the past few years I've done these scenarios: 1: Having a seperate .txt file with a character as the version # then simply comparing them through code and downloading the new .plist, then saving that .txt to the user's NSDocumentDirectory along with the .plist to compare again in the future, and 2: Actually checking the server's file modification date, which worked even better, as there was no .txt file to download along with the .plist (the less stuff to download the better)
But, now I want to try a different way to account for the fact that I ship a .plist file in the App Bundle. Since the .plist file creation date is always later then the server date for new users, they don't get the new .plist file, whereas older users of the app get the new file. Sure, on the first app launch I could grab the server's modification date and overwrite the app's since I copy it from the main bundle to the NSDocumentDirectory, but I don't think I want to go that route, as I've never liked checking launch counts.
Basically, it needs to continue to be lightweight in network request time and be reliable like it's been for me. I was thinking about creating a version # key in my .plist and simply comparing that with the local .plist, but I highly doubt this will be as lightweight, as I would have to download the whole .plist into an NSDictionary first before I can compare the key values.
I'm really sorry this post is long, and I appreciate your help!
Why not ship the app with out the data_source.plist file and download it on first launch, or any other time it does not exist on disk (you never know). After that, you could send a HEAD request and check the modification date (maybe even the e-tag), and download as necessary.
UPDATE:
Depending on how much control you have over the server, you could add a hash of the file to the response headers (as mentioned in the comments: MD5,SHA*) along side Last-Modified.
You could add the data_source.plist to the bundle at build time, along with last_modified.plist where you can set the hash, last modified, and any other meta data you want, as starting point.
Checking for updates could look something like:
Send HEAD request for http://server.com/data_source.plist
Pull Last-Modified (and hash if you can send it) from the response headers
Validate against corresponding values in last_modifed.plist
Download updated data_source.plist if needed
If the download was successful, update last_modifed.plist with new meta data (last modified and has, be sure pull this from actual download response headers).
This way, the user has something to start with, and the app can download the resource when needed.
The advantage of a HEAD request is it is light weight since there is no message body, but returns the same response headers as a GET request. It is a common method to check if a resource has been updated. The trick with your scenario is to get a starting point onto the device at build time.
There very well may be an answer to this already on SO, but I'm not familiar enough with compression formats to know if they're applicable to my case. So here's what I need:
1) Download a *.tgz file that is greater than 200MB.
2) Unpack it to a specified subdirectory of the Documents folder.
I know how to make the connection and begin downloading. But how do I download to an actual file (rather than storing it in memory), and once this download is complete how do I unpack it to my desired location?
To save the downloaded data to a file, see this SO-question and answer(s): The easiest way to write NSData to a file
To uncompress .tgz-files, see this question and answer(s): "Untar" file on iPhone
To download large files, see this question and answer(s): How to download large files using objective c on iphone
(Google is an awesome tool, really.)
Just as a sidenote, an app shouldn't download 200MB of data. It is time- and bandwith consuming and may cause Apple to reject your app.
Forget NSURLConnection; use ASIHTTPConnection (google it) which has an easy save to file option. (And resumes failed downloads too)
I don't know the answer to tar/gzip. My application uses zips instead and http://code.google.com/p/ziparchive/wiki/PageName does the trick.
I am implementing resumable file downloading for the iPhone, and I need to know how I can tell whether a file I have previously downloaded is complete or not before I attempt to redownload.
I've decided to use a '.part' or similar extension for files that are in progress of being downloaded. Then once the -(void)connectionDidFinishLoading:(NSURLConnection *)connection method executes, I will rename it.
You'll need to store the information about the size of the complete file somewhere that can be matched up with the partially downloaded file -- or, in the least, something that indicates the file is partially downloaded.
When your app wants to do anything with any of the downloaded files, it needs to check for partially downloaded content (i.e. actual size of data you have < complete file size) -- if it's only downloaded partially, it needs to kick off a resume download.
Without more specific info, can't say much more than that!